The deadly new strain of bird flu has spread further on the mainland, with two people in Henan province confirmed yesterday as infected with H7N9, the first cases in the region.
Shanghai reported two new deaths, those of a 67-year-old woman who died on Saturday and a 77-year-old man who died yesterday morning, bringing the national death toll to 13.
Three new cases were confirmed in Shanghai yesterday, four in Zhejiang province and two in neighbouring Jiangsu , giving a national total of 60.
A 34-year-old restaurant chef in the city of Kaifeng , Weishi county, was admitted to a county hospital on April 6 after developing flu symptoms, according to health authorities in Henan, one of the most densely populated provinces. He was sent to a Kaifeng city hospital on Tuesday and was now in critical condition.
The other case in the province is a 65-year-old farmer from Zhoukou who had frequent contact with live poultry at his home. He developed symptoms last Monday and was admitted to the local hospital on Wednesday. He was now in stable condition after receiving treatment, Henan health authorities said. No flu symptoms have developed in 19 people who had close contact with the two Henan victims, according to Xinhua.
Three cases have now been reported outside the original clusters in the eastern Yangtze River area, including one in Beijing, but the spread of cases indicated nothing out of the ordinary so far, the China representative of the World Health Organisation, Michael O'Leary, said.
"There's no way to predict how it will spread but it's not surprising if we have new cases in different places like we do in Beijing," he said yesterday.
He stressed that there was still no indication of human-to-human transmission. "That's a key factor in this situation," he said. "As far as we know, all the cases were individually infected in a sporadic and unconnected way."
The husband of an H7N9 patient in Shanghai was recently infected, but O'Leary said there was no cause for alarm. "If there are only very rare cases … that's different from the ease of transmission from person to person. It's that ease of transmission that we are concerned about, and there's no evidence of that yet."
Hong Kong health minister Dr Ko Wing-man warned that poultry workers were at the highest risk of H7N9 infection because most of the mainland cases had a history of contact with poultry.
But there was no need to stop sales of live chickens because they were imported from Guangdong, which had no H7N9 cases, and they were tested for the H7 virus before being sold, he said.
He would be meeting representatives of the poultry industry in the next few days to discuss raising awareness of prevention.
"As well as protecting themselves, poultry workers are also a line of defence for Hong Kong's general public," he said.
Additional reporting by Reuters
View H7N9 map  in a larger map
Click on each balloon for more information on individual patients infected: blue, patients infected with the H7N9 virus under treatment; red, those infected with H7N9 who have died; yellow, those who have fully recovered; and pink, those infected other types of the Influenza A virus, including H1N1.